Some may consider kiwis the perfect fruit -- each one contains as much potassium as a banana, more than the recommended daily dose of vitamin C, and high levels of vitamins A and E and beta-carotene. Kiwis are also high in antioxidants and fiber. But for individuals with a kiwi allergy, this fruit can cause reactions that range from itching and inflammation in the mouth and throat to abdominal pain, difficulty breathing, and even anaphylactic shock.

Although kiwis don't get as much exposure as more common allergens like wheat and nuts, kiwi allergies are increasing worldwide. Why is it becoming such a prevalent allergen? A major reason is that it cross-reacts with many other foods and substances, including birch pollen, avocado, banana, rye, and hazelnuts. This means that the allergens share similar properties and can react the same way in the body. Kiwis can even be problematic for people with latex sensitivities -- although kiwis and latex seem totally different, they share common epitopes, so the immune system sees them as the same thing.

Researchers suspect a geographic component to the increase in kiwi allergies -- there's more likely to be more kiwi allergies where there is more birch. Anyone with birch or latex allergies is at a greater risk for a kiwi allergy. And while experts don't recommend eliminating kiwis from your diet if you have these allergies, they do advise discussing it with your allergist if you experience any kind of allergic reaction to kiwis.